The following remarks can pretend to be nothing more than a few loose and undigested thoughts upon a subject, which has recently occupied the attention of many men, and obtained an extraordinary vogue in the world. It were to be wished, that the task had fallen into the hands of a writer whose studies were more familiar with all the sciences which bear more or less on the topic I propose to consider: but, if abler and more competent men pass it by, I feel disposed to plant myself in the breach, and to offer suggestions which may have the fortune to lead others, better fitted for the office than myself, to engage in the investigation. One advantage I may claim, growing out of my partial deficiency. It is known not to be uncommon for a man to stand too near to the subject of his survey, to allow him to obtain a large view of it in all its bearings. I am no anatomist: I simply take my stand upon the broad ground of the general philosophy of man.
It is a very usual thing for fanciful theories to have their turn amidst the eccentricities of the human mind, and then to be heard of no more. But it is perhaps no ill occupation, now and then, for an impartial observer, to analyse these theories, and attempt to blow away the dust which will occasionally settle on the surface of science. If phrenology, as taught by Gall and Spurzheim, be a truth, I shall probably render a service to that truth, by endeavouring to shew where the edifice stands in need of more solid supports than have yet been assigned to it. If it be a falshood, the sooner it is swept away to the gulph of oblivion the better. Let the inquisitive and the studious fix their minds on more substantial topics, instead of being led away by gaudy and deceitful appearances. The human head, that crowning capital of the column of man, is too interesting a subject, to be the proper theme of every dabbler. And it is obvious, that the professors of this so called discovery, if they be rash and groundless in their assertions, will be in danger of producing momentous errors, of exciting false hopes never destined to be realised, and of visiting with pernicious blasts the opening buds of excellence, at the time when they are most exposed to the chance of destruction.
I shall set out with acknowledging, that there is, as I apprehend, a science in relation to the human head, something like what Plato predicates of the statue hid in a block of marble. It is really contained in the block; but it is only the most consummate sculptor, that can bring it to the eyes of men, and free it from all the incumbrances, which, till he makes application of his art to it, surround the statue, and load it with obscurities and disfigurement. The man, who, without long study and premeditation, rushes in at once, and expects to withdraw the curtain, will only find himself disgraced by the attempt.
There is a passage in an acute writer(39), whose talents singularly fitted him, even when he appeared totally immerged in mummery and trifles, to illustrate the most important truths, that is applicable to the point I am considering.
(39) Sterne, Tristram Shandy, Vol. 1.
"Pray, what was that man's name,—for I write in such a hurry, I have no time to recollect or look for it,—who first made the observation, 'That there was great inconstancy in our air and climate?' Whoever he was, it was a just and good observation in him. But the corollary drawn from it, namely, 'That it is this which has furnished us with such a variety of odd and whimsical characters;'—that was not his;—it was found out by another man, at least a century and a half after him. Then again, that this copious storehouse of original materials is the true and natural cause that our comedies are so much better than those of France, or any others that have or can be wrote upon the continent;—that discovery was not fully made till about the middle of king William's reign, when the great Dryden, in writing one of his long prefaces (if I mistake not), most fortunately hit upon it. Then, fourthly and lastly, that this strange irregularity in our climate, producing so strange an irregularity in our characters, cloth thereby in some sort make us amends, by giving us somewhat to make us merry with, when the weather will not suffer us to go out of doors,—that observation is my own; and was struck out by me this very rainy day, March 26, 1759, and betwixt the hour of nine and ten in the morning.
"Thus—thus, my fellow-labourers and associates in this great harvest of our learning, now ripening before our eyes; thus it is, by slow steps of casual increase, that our knowledge physical, metaphysical, physiological, polemical, nautical, mathematical, aenigmatical, technical, biographical, romantical, chemical, and obstetrical, with fifty other branches of it, (most of them ending, as these do, in ical,) has, for these two last centuries and more, gradually been creeping upwards towards that acme of their perfections, from which, if we may form a conjecture from the advantages of these last seven years, we cannot possibly be far off."
Nothing can be more true, than the proposition ludicrously illustrated in this passage, that real science is in most instances of slow growth, and that the discoveries which are brought to perfection at once, are greatly exposed to the suspicion of quackery. Like the ephemeron fly, they are born suddenly, and may be expected to die as soon.
Lavater, the well known author of Essays on Physiognomy, appears to have been born seventeen years before the birth of Gall. He attempted to reduce into a system the indications of human character that are to be found in the countenance. Physiognomy, as a subject of ingenious and probable conjecture, was well known to the ancients. But the test, how far any observations that have been made on the subject are worthy the name of a science, will lie in its application by the professor to a person respecting whom he has had no opportunity of previous information. Nothing is more easy, when a great warrior, statesman, poet, philosopher or philanthropist is explicitly placed before us, than for the credulous inspector or fond visionary to examine the lines of his countenance, and to point at the marks which should plainly shew us that he ought to have been the very thing that he is. This is the very trick of gipsies and fortune-tellers. But who ever pointed to an utter stranger in the street, and said, I perceive by that man's countenance that he is one of the great luminaries of the world? Newton, or Bacon, or Shakespear would probably have passed along unheeded. Instances of a similar nature occur every day. Hence it plainly appears that, whatever may hereafter be known on the subject, we can scarcely to the present time be said to have overstepped the threshold. And yet nothing can be more certain than that there is a science of physiognomy, though to make use of an illustration already cited, it has not to this day been extricated out of the block of marble in which it is hid. Human passions, feelings and modes of thinking leave their traces on the countenance: but we have not, thus far, left the dame's school in this affair, and are not qualified to enter ourselves in the free-school for more liberal enquiries.
The writings of Lavater on the subject of physiognomy are couched in a sort of poetic prose, overflowing with incoherent and vague exclamations, and bearing small resemblance to a treatise in which the elements of science are to be developed. Their success however was extraordinary; and it was probably that success, which prompted Gall first to turn his attention from the indications of character that are to be found in the face of man, to the study of the head generally, as connected with the intellectual and moral qualities of the individual.
It was about four years before the commencement of the present century, that Gall appears to have begun to deliver lectures on the structure and external appearances of the human head. He tells us, that his attention was first called to the subject in the ninth year of his age (that is, in the year 1767), and that he spent thirty years in the private meditation of his system, before he began to promulgate it. Be that as it will, its most striking characteristic is that of marking out the scull into compartments, in the same manner as a country delineated on a map is divided into districts, and assigning a different faculty or organ to each. In the earliest of these diagrams that has fallen under my observation, the human scull is divided into twenty-seven compartments.
I would say of craniology, as I have already said of physiognomy, that there is such a science attainable probably by man, but that we have yet made scarcely any progress in the acquiring it. As certain lines in the countenance are indicative of the dispositions of the man, so it is reasonable to believe that a certain structure of the head is in correspondence with the faculties and propensities of the individual.
Thus far we may probably advance without violating a due degree of caution. But there is a wide distance between this general statement, and the conduct of the man who at once splits the human head into twenty-seven compartments.
The exterior appearance of the scull is affirmed to correspond with the structure of the brain beneath. And nothing can be more analogous to what the deepest thinkers have already confessed of man, than to suppose that there is one structure of the brain better adapted for intellectual purposes than another. There is probably one structure better adapted than another, for calculation, for poetry, for courage, for cowardice, for presumption, for diffidence, for roughness, for tenderness, for self-control and the want of it. Even as some have inherently a faculty adapted for music or the contrary(40).
(40) See above, Essay II.
But it is not reasonable to believe that we think of calculation with one portion of the brain, and of poetry with another.
It is very little that we know of the nature of matter; and we are equally ignorant as to the substance, whatever it is, in which the thinking principle in man resides. But, without adventuring in any way to dogmatise on the subject, we find so many analogies between the thinking principle, and the structure of what we call the brain, that we cannot but regard the latter as in some way the instrument of the former.
Now nothing can be more certain respecting the thinking principle, than its individuality. It has been said, that the mind can entertain but one thought at one time; and certain it is, from the nature of attention, and from the association of ideas, that unity is one of the principal characteristics of mind. It is this which constitutes personal identity; an attribute that, however unsatisfactory may be the explanations which have been given respecting it, we all of us feel, and that lies at the foundation of all our voluntary actions, and all our morality.
Analogous to this unity of thought and mind, is the arrangement of the nerves and the brain in the human body. The nerves all lead up to the brain; and there is a centrical point in the brain itself, in which the reports of the senses terminate, and at which the action of the will may be conceived to begin. This, in the language of our fathers, was called the "seat of the soul."
We may therefore, without departing from the limits of a due caution and modesty, consider this as the throne before which the mind holds its court. Hither the senses bring in their reports, and hence the sovereign will issues his commands. The whole system appears to be conducted through the instrumentality of the nerves, along whose subtle texture the feelings and impressions are propagated. Between the reports of the senses and the commands of the will, intervenes that which is emphatically the office of the mind, comprising meditation, reflection, inference and judgment. How these functions are performed we know not; but it is reasonable to believe that the substance of the brain or of some part of the brain is implicated in them.
Still however we must not lose sight of what has been already said, that in the action of the mind unity is an indispensible condition. Our thoughts can only hold their council and form their decrees in a very limited region. This is their retreat and strong hold; and the special use and functions of the remoter parts of the brain we are unable to determine; so utterly obscure and undefined is our present knowledge of the great ligament which binds together the body and the thinking principle.
Enough however results from this imperfect view of the ligament, to demonstrate the incongruity and untenableness of a doctrine which should assign the indications of different functions, exercises and propensities of the mind to the exterior surface of the scull or the brain. This is quackery, and is to be classed with chiromancy, augury, astrology, and the rest of those schemes for discovering the future and unknown, which the restlessness and anxiety of the human mind have invented, built upon arbitrary principles, blundered upon in the dark, and having no resemblance to the march of genuine science. I find in sir Thomas Browne the following axioms of chiromancy: "that spots in the tops of the nails do signifie things past; in the middle, things present; and at the bottom, events to come: that white specks presage our felicity; blue ones our misfortunes: that those in the nails of the thumb have significations of honour, in the forefinger, of riches, and so respectively in the rest."
Science, to be of a high and satisfactory character, ought to consist of a deduction of causes and effects, shewing us not merely that a thing is so, but why it is as it is, and cannot be otherwise. The rest is merely empirical; and, though the narrowness of human wit may often drive us to this; yet it is essentially of a lower order and description. As it depends for its authority upon an example, or a number of examples, so examples of a contrary nature may continually come in, to weaken its force, or utterly to subvert it. And the affair is made still worse, when we see, as in the case of craniology, that all the reasons that can be deduced (as here from the nature of mind) would persuade us to believe, that there can be no connection between the supposed indications, and the things pretended to be indicated.
Craniology, or phrenology, proceeds exactly in the same train, as chiromancy, or any of those pretended sciences which are built merely on assumption or conjecture. The first delineations presented to the public, marked out, as I have said, the scull into compartments, in the same manner as a country delineated on a map is divided into districts. Geography is a real science, and accordingly, like other sciences, has been slow and gradual in its progress. At an early stage travellers knew little more than the shores and islands of the Mediterranean. Afterwards, they passed the straits of Hercules, and entered into the Atlantic. At length the habitable world was distributed into three parts, Europe, Asia, and Africa. More recently, by many centuries, came the discovery of America. It is but the other day comparatively, that we found the extensive island of New Holland in the Southern Ocean. The ancient geographers placed an elephant or some marine monster in the vacant parts of their maps, to signify that of these parts they knew nothing. Not so Dr. Gall. Every part of his globe of the human Scull, at least with small exceptions, is fully tenanted; and he, with his single arm, has conquered a world.
The majority of the judgments that have been divulged by the professors of this science, have had for their subjects the sculls of men, whose habits and history have been already known. And yet with this advantage the errors and contradictions into which their authors have fallen are considerably numerous. Thus I find, in the account of the doctor's visit to the House of Correction and the Hospital of Torgau in July 1805, the following examples.
"Every person was desirous to know what Dr. Gall would say about T—, who was known in the house as a thief full of cunning, and who, having several times made his escape, wore an additional iron. It was surprising, that he saw in him far less of the organ of cunning, than in many of the other prisoners. However it was proved, that examples, and conversation with other thieves in the house, had suggested to him the plan for his escape, and that the stupidity which he possesses was the cause of his being retaken."
"We were much surprised to be told, that M., in whom Dr. Gall had not discovered the organ of representation, possessed extraordinary abilities in imitating the voice of animals; but we were convinced after enquiries, that his talent was not a natural one, but acquired by study. He related to us that, when he was a Prussian soldier garrisoned at Berlin, he used to deceive the waiting women in the Foundling Hospital by imitating the voice of exposed infants, and sometimes counterfeited the cry of a wild drake, when the officers were shooting ducks."
"Of another Dr. Gall said, His head is a pattern of inconstancy and confinement, and there appears not the least mark of the organ of courage. This rogue had been able to gain a great authority among his fellow-convicts. How is this to be reconciled with the want of constancy which his organisation plainly indicates? Dr. Gall answered, He gained his ascendancy not by courage, but by cunning."
It is well known, that in Thurtel, who was executed for one of the most cold-blooded and remorseless murders ever heard of, the phrenologists found the organ of benevolence uncommonly large.
In Spurzheim's delineation of the human head I find six divisions of organs marked out in the little hemisphere over the eye, indicating six different dispositions. Must there not be in this subtle distribution much of what is arbitrary and sciolistic?
It is to be regretted, that no person skilful in metaphysics, or the history of the human mind, has taken a share in this investigation. Many errors and much absurdity would have been removed from the statements of these theorists, if a proper division had been made between those attributes and propensities, which by possibility a human creature may bring into the world with him, and those which, being the pure growth of the arbitrary institutions of society, must be indebted to those institutions for their origin. I have endeavoured in a former Essay(41) to explain this distinction, and to shew how, though a human being cannot be born with an express propensity towards any one of the infinite pursuits and occupations which may be found in civilised society, yet that he may be fitted by his external or internal structure to excel in some one of those pursuits rather than another. But all this is overlooked by the phrenologists. They remark the various habits and dispositions, the virtues and the vices, that display themselves in society as now constituted, and at once and without consideration trace them to the structure that we bring into the world with us.
(41) See above, Essay II.
Certainly many of Gall's organs are a libel upon our common nature. And, though a scrupulous and exact philosopher will perhaps confess that he has little distinct knowledge as to the design with which "the earth and all that is therein" were made, yet he finds in it so much of beauty and beneficent tendency, as will make him extremely reluctant to believe that some men are born with a decided propensity to rob, and others to murder. Nor can any thing be more ludicrous than this author's distinction of the different organs of memory—of things, of places, of names, of language, and of numbers: organs, which must be conceived to be given in the first instance long before names or language or numbers had an existence. The followers of Gall have in a few instances corrected this: but what their denominations have gained in avoiding the grossest absurdities of their master, they have certainly lost in explicitness and perspicuity.
There is a distinction, not unworthy to be attended to, that is here to be made between Lavater's system of physiognomy, and Gall's of craniology, which is much in favour of the former. The lines and characteristic expressions of the face which may so frequently be observed, are for the most part the creatures of the mind. This is in the first place a mode of observation more agreeable to the pride and conscious elevation of man, and is in the next place more suitable to morality, and the vindication of all that is most admirable in the system of the universe. It is just, that what is most frequently passing in the mind, and is entertained there with the greatest favour, should leave its traces upon the countenance. It is thus that the high and exalted philosopher, the poet, and the man of benevolence and humanity are sometimes seen to be such by the bystander and the stranger. While the malevolent, the trickish, and the grossly sensual, give notice of what they are by the cast of their features, and put their fellow-creatures upon their guard, that they may not be made the prey of these vices.
But the march of craniology or phrenology, by whatever name it is called, is directly the reverse of this. It assigns to us organs, as far as the thing is explained by the professors either to the public or to their own minds, which are entailed upon us from our birth, and which are altogether independent, or nearly so, of any discipline or volition that can be exercised by or upon the individual who drags their intolerable chain. Thus I am told of one individual that he wants the organ of colour; and all the culture in the world can never supply that defect, and enable him to see colour at all, or to see it as it is seen by the rest of mankind. Another wants the organ of benevolence; and his case is equally hopeless. I shrink from considering the condition of the wretch, to whom nature has supplied the organs of theft and murder in full and ample proportions. The case is like that of astrology
(Their stars are more in fault than they),
with this aggravation, that our stars, so far as the faculty of prediction had been supposed to be attained, swayed in few things; but craniology climbs at once to universal empire; and in her map, as I have said, there are no vacant places, no unexplored regions and happy wide-extended deserts.
It is all a system of fatalism. Independently of ourselves, and far beyond our control, we are reserved for good or for evil by the predestinating spirit that reigns over all things. Unhappy is the individual who enters himself in this school. He has no consolation, except the gratified wish to know distressing truths, unless we add to this the pride of science, that he has by his own skill and application purchased for himself the discernment which places him in so painful a preeminence. The great triumph of man is in the power of education, to improve his intellect, to sharpen his perceptions, and to regulate and modify his moral qualities. But craniology reduces this to almost nothing, and exhibits us for the most part as the helpless victims of a blind and remorseless destiny.
In the mean time it is happy for us, that, as this system is perhaps the most rigorous and degrading that was ever devised, so it is in almost all instances founded upon arbitrary assumptions and confident assertion, totally in opposition to the true spirit of patient and laborious investigation and sound philosophy.
It is in reality very little that we know of the genuine characters of men. Every human creature is a mystery to his fellow. Every human character is made up of incongruities. Of nearly all the great personages in history it is difficult to say what was decidedly the motive in which their actions and system of conduct originated. We study what they did, and what they said; but in vain. We never arrive at a full and demonstrative conclusion. In reality no man can be certainly said to know himself. "The heart of man is deceitful above all things."
But these dogmatists overlook all those difficulties, which would persuade a wise man to suspend his judgment, and induce a jury of philosophers to hesitate for ever as to the verdict they would pronounce. They look only at the external character of the act by which a man honours or disgraces himself. They decide presumptuously and in a lump, This man is a murderer, a hero, a coward, the slave of avarice, or the votary of philanthropy; and then, surveying the outside of his head, undertake to find in him the configuration that should indicate these dispositions, and must be found in all persons of a similar character, or rather whose acts bear the same outward form, and seem analogous to his.
Till we have discovered the clue that should enable us to unravel the labyrinth of the human mind, it is with small hopes of success that we should expect to settle the external indications, and decide that this sort of form and appearance, and that class of character, will always be found together.
But it is not to be wondered at, that these disorderly fragments of a shapeless science should become the special favourites of the idle and the arrogant. Every man (and every woman), however destitute of real instruction, and unfitted for the investigation of the deep or the sublime mysteries of our nature, can use his eyes and his hands. The whole boundless congregation of mankind, with its everlasting varieties, is thus at once subjected to the sentence of every pretender:
And fools rush in, where angels fear to tread.
Nothing is more delightful to the headlong and presumptuous, than thus to sit in judgment on their betters, and pronounce ex cathedra on those, "whose shoe-latchet they are not worthy to stoop down and unloose." I remember, after lord George Gordon's riots, eleven persons accused were set down in one indictment for their lives, and given in charge to one jury. But this is a mere shadow, a nothing, compared with the wholesale and indiscriminating judgment of the vulgar phrenologist.
It can scarcely be imputed to me as profane, if I venture to put down a few sceptical doubts on the science of astronomy. All branches of knowledge are to be considered as fair subjects of enquiry: and he that has never doubted, may be said, in the highest and strictest sense of the word, never to have believed.
The first volume that furnished to me the groundwork of the following doubts, was the book commonly known by the name of Guthrie's Geographical Grammar, many parts and passages of which engaged my attention in my own study, in the house of a rural schoolmaster, in the year 1772. I cannot therefore proceed more fairly than by giving here an extract of certain passages in that book, which have relation to the present subject. I know not how far they have been altered in the edition of Guthrie which now lies before me, from the language of the book then in my possession; but I feel confident that in the main particulars they continue the same(42).
(42) The article Astronomy, in this book, appears to have been writtenby the well known James Ferguson.
"In passing rapidly over the heavens with his new telescope, the universe increased under the eye of Herschel; 44,000 stars, seen in the space of a few degrees, seemed to indicate that there were seventy-five millions in the heavens. But what are all these, when compared with those that fill the whole expanse, the boundless field of aether?
"The immense distance of the fixed stars from our earth, and from each other, is of all considerations the most proper for raising our ideas of the works of God. Modern discoveries make it probable that each of these stars is a sun, having planets and comets revolving round it, as our sun has the earth and other planets revolving round him.—A ray of light, though its motion is so quick as to be commonly thought instantaneous, takes up more time in travelling from the stars to us, than we do in making a West-India voyage. A sound, which, next to light, is considered as the quickest body we are acquainted with, would not arrive to us from thence in 50,000 years. And a cannon-ball, flying at the rate of 480 miles an hour, would not reach us in 700,000 years.
"From what we know of our own system, it may be reasonably concluded, that all the rest are with equal wisdom contrived, situated, and provided with accommodations for rational inhabitants.
"What a sublime idea does this suggest to the human imagination, limited as are its powers, of the works of the Creator! Thousands and thousands of suns, multiplied without end, and ranged all around us, at immense distances from each other, attended by ten thousand times ten thousand worlds, all in rapid motion, yet calm, regular and harmonious, invariably keeping the paths prescribed them: and these worlds peopled with myriads of intelligent beings, formed for endless progression in perfection and felicity!"
The thought that would immediately occur to a dispassionate man in listening to this statement, would be, What a vast deal am I here called on to believe!
Now the first rule of sound and sober judgment, in encountering any story, is that, in proportion to the magnitude and seemingly incredible nature of the propositions tendered to our belief, should be the strength and impregnable nature of the evidence by which those propositions are supported.
It is not here, as in matters of religion, that we are called upon by authority from on high to believe in mysteries, in things above our reason, or, as it may be, contrary to our reason. No man pretends to a revelation from heaven of the truths of astronomy. They have been brought to light by the faculties of the human mind, exercised upon such facts and circumstances as our industry has set before us.
To persons not initiated in the rudiments of astronomical science, they rest upon the great and high-sounding names of Galileo, Kepler, Halley and Newton. But, though these men are eminently entitled to honour and gratitude from their fellow-mortals, they do not stand altogether on the same footing as Matthew, Mark, Luke and John, by whose pens has been recorded "every word that proceedeth out of the mouth of God."
The modest enquirer therefore, without pretending to put himself on an equality with these illustrious men, may be forgiven, when he permits himself to suggest a few doubts, and presumes to examine the grounds upon which he is called upon to believe all that is contained in the above passages.
Now the foundations upon which astronomy, as here delivered, is built, are, first, the evidence of our senses, secondly, the calculations of the mathematician, and, in the third place, moral considerations. These have been denominated respectively, practical astronomy, scientific, and theoretical.
As to the first of these, it is impossible for us on this occasion not to recollect what has so often occurred as to have grown into an every-day observation, of the fallibility of our senses.
It may be doubted however whether this is a just statement. We are not deceived by our senses, but deceived in the inference we make from our sensations. Our sensations respecting what we call the external world, are chiefly those of length, breadth and solidity, hardness and softness, heat and cold, colour, smell, sound and taste. The inference which the generality of mankind make in relation to these sensations is, that there is something out of ourselves corresponding to the impressions we receive; in other words, that the causes of our sensations are like to the sensations themselves. But this is, strictly speaking, an inference; and, if the cause of a sensation is not like the sensation, it cannot precisely be affirmed that our senses deceive us. We know what passes in the theatre of the mind; but we cannot be said absolutely to know any thing, more.
Modern philosophy has taught us, in certain cases, to controvert the position, that the causes of our sensations are like to the sensations themselves. Locke in particular has called the attention of the reasoning part of mankind to the consideration, that heat and cold, sweet and bitter, and odour offensive or otherwise, are perceptions, which imply a percipient being, and cannot exist in inanimate substances. We might with equal propriety ascribe pain to the whip that beats us, or pleasure to the slight alternation of contact in the person or thing that tickles us, as suppose that heat and cold, or taste, or smell are any thing but sensations.
The same philosophers who have called our attention to these remarks, have proceeded to shew that the causes of our sensations of sound and colour have no precise correspondence, do not tally with the sensations we receive. Sound is the result of a percussion of the air. Colour is produced by the reflection of the rays of light; so that the same object, placed in a position, different as to the spectator, but in itself remaining unaltered, will produce in him a sensation of different colours, or shades of colour, now blue, now green, now brown, now black, and so on. This is the doctrine of Newton, as well as of Locke.
It follows that, if there were no percipient being to receive these sensations, there would be no heat or cold, no taste, no smell, no sound, and no colour.
Aware of this difference between our sensations in certain cases and the causes of these sensations, Locke has divided the qualities of substances in the material universe into primary and secondary, the sensations we receive of the primary representing the actual qualities of material substances, but the sensations we receive of what he calls the secondary having no proper resemblance to the causes that produce them.
Now, if we proceed in the spirit of severe analysis to examine the primary qualities of matter, we shall not perhaps find so marked a distinction between those and the secondary, as the statement of Locke would have led us to imagine.
The Optics of Newton were published fourteen years later than Locke's Essay concerning Human Understanding.
In endeavouring to account for the uninterrupted transmission of rays of light through transparent substances, however hard they may be found to be, Newton has these observations.
"Bodies are much more rare and porous, than is commonly believed. Water is nineteen times lighter, and by consequence nineteen times rarer, than gold; and gold is so rare, as very readily, and without the least opposition, to transmit the magnetic effluvia, and easily to admit quicksilver into its pores, and to let water pass through it. From all which we may conclude, that gold has more pores than solid parts, and by consequence that water has above forty times more pores than parts. And he that shall find out an hypothesis, by which water may be so rare, and yet not capable of compression by force, may doubtless, by the same hypothesis, make gold, and water, and all other bodies, as much rarer as he pleases, so that light may find a ready passage through transparent substances(43)."
(43) Newton, Optics, Book II, Part III, Prop. viii.
Again: "The colours of bodies arise from the magnitude of the particles that reflect them. Now, if we conceive these particles of bodies to be so disposed among themselves, that the intervals, or empty spaces between them, may be equal in magnitude to them all; and that these particles may be composed of other particles much smaller, which have as much empty space between them as equals all the magnitudes of these smaller particles; and that in like manner these smaller particles are again composed of others much smaller, all which together are equal to all the pores, or empty spaces, between them; and so on perpetually till you come to solid particles, such as have no pores, or empty spaces within them: and if in any gross body there be, for instance, three such degrees of particles, the least of which are solid; this body will have seven times more pores than solid parts. But if there be four such degrees of particles, the least of which are solid, the body will have fifteen times more pores than solid parts. If there be five degrees, the body will have one and thirty times more pores than solid parts. If six degrees, the body will have sixty and three times more pores than solid parts. And so on perpetually(44)."
(44) Ibid.
In the Queries annexed to the Optics, Newton further suggests an opinion, that the rays of light are repelled by bodies without immediate contact. He observes that:
"Where attraction ceases, there a repulsive virtue ought to succeed. And that there is such a virtue, seems to follow from the reflexions and inflexions of the rays of light. For the rays are repelled by bodies, in both these cases, without the immediate contact of the reflecting or inflecting body. It seems also to follow from the emission of light; the ray, so soon as it is shaken off from a shining body by the vibrating motion of the parts of the body, and gets beyond the reach of attraction, being driven away with exceeding great velocity. For that force, which is sufficient to turn it back in reflexion, may be sufficient to emit it. It seems also to follow from the production of air and vapour: the particles, when they are shaken off from bodies by heat or fermentation, so soon as they are beyond the reach of the attraction of the body, receding from it and also from one another, with great strength; and keeping at a distance, so as sometimes to take up a million of times more space than they did before, in the form of a dense body."
Newton was of opinion that matter was made up, in the last resort, of exceedingly small solid particles, having no pores, or empty spaces within them. Priestley, in his Disquisitions relating to Matter and Spirit, carries the theory one step farther; and, as Newton surrounds his exceedingly small particles with spheres of attraction and repulsion, precluding in all cases their actual contact, Priestley is disposed to regard the centre of these spheres as mathematical points only. If there is no actual contact, then by the very terms no two particles of matter were ever so near to each other, but that they might be brought nearer, if a sufficient force could be applied for that purpose. You had only another sphere of repulsion to conquer; and, as there never is actual contact, the whole world is made up of one sphere of repulsion after another, without the possibility of ever arriving at an end.
"The principles of the Newtonian philosophy," says our author, "were no sooner known, than it was seen how few in comparison, of the phenomena of nature, were owing to solid matter, and how much to powers, which were only supposed to accompany and surround the solid parts of matter. It has been asserted, and the assertion has never been disproved, that for any thing we know to the contrary, all the solid matter in the solar system might be contained within a nutshell(45)."
(45) Priestley, Disquisitions, Section II. I know not by whom thisillustration was first employed. Among other authors, I find, inFielding (Joseph Andrews, Book II, Chap. II), a sect of philosophersspoken of, who "can reduce all the matter of the world into a nutshell."
It is then with senses, from the impressions upon which we are impelled to draw such false conclusions, and that present us with images altogether unlike any thing that exists out of ourselves, that we come to observe the phenomena of what we call the universe. The first observation that it is here incumbent on us to make, and which we ought to keep ever at hand, to be applied as occasion may offer, is the well known aphorism of Socrates, that "we know only this, that we know nothing." We have no compass to guide us through the pathless waters of science; we have no revelation, at least on the subject of astronomy, and of the unnumbered inhabitable worlds that float in the ocean of ether; and we are bound therefore to sail, as the mariners of ancient times sailed, always within sight of land. One of the earliest maxims of ordinary prudence, is that we ought ever to correct the reports of one sense by the assistance of another sense. The things we here speak of are not matters of faith; and in them therefore it is but reason, that we should imitate the conduct of Didymus the apostle, who said, "Except I put my fingers into the prints of the nails, and thrust my hand into his side, I will not believe." My eyes report to me an object, as having a certain magnitude, texture, and roughness or smoothness; but I require that my hands should confirm to me the evidence of my eyes. I see something that appears to be an island at an uncertain distance from the shore; but, if I am actuated by a laudable curiosity, and wish to possess a real knowledge, I take a boat, and proceed to ascertain by nearer inspection, whether that which I imagined to be an island is an island or no.
There are indeed many objects with which we are conversant, that are in so various ways similar to each other, that, after having carefully examined a few, we are satisfied upon slighter investigation to admit the dimensions and character of others. Thus, having measured with a quadrant the height of a tower, and found on the narrowest search and comparison that the report of my instrument was right, I yield credit to this process in another instance, without being at the trouble to verify its results in any more elaborate method.
The reason why we admit the inference flowing from our examination in the second instance, and so onward, with less scrupulosity and scepticism than in the first, is that there is a strict resemblance and analogy in the two cases. Experience is the basis of our conclusions and our conduct. I strike against a given object, a nail for example, with a certain degree of force, because I have remarked in myself and others the effect of such a stroke. I take food and masticate it, because I have found that this process contributes to the sound condition of my body and mind. I scatter certain seeds in my field, and discharge the other functions of an agriculturist, because I have observed that in due time the result of this industry is a crop. All the propriety of these proceedings depends upon the exact analogy between the old case and the new one. The state of the affair is still the same, when my business is merely that of an observer and a traveller. I know water from earth, land from sea, and mountains from vallies, because I have had experience of these objects, and confidently infer that, when certain appearances present themselves to my organs of sight, I shall find the same results to all my other senses, as I found when such appearances occurred to me before.
But the interval that divides the objects which occur upon and under the earth, and are accessible in all ways to our examination, on the one hand, and the lights which are suspended over our heads in the heavens on the other, is of the broadest and most memorable nature. Human beings, in the infancy of the world, were contented reverently to behold these in their calmness and beauty, perhaps to worship them, and to remark the effects that they produced, or seemed to produce, upon man and the subjects of his industry. But they did not aspire to measure their dimensions, to enquire into their internal frame, or to explain the uses, far removed from our sphere of existence, which they might be intended to serve.
It is however one of the effects of the improvement of our intellect, to enlarge our curiosity. The daringness of human enterprise is one of the prime glories of our nature. It is our boast that we undertake to "measure earth, weigh air, and state the tides." And, when success crowns the boldness of our aspirations after what vulgar and timorous prudence had pronounced impossible, it is then chiefly that we are seen to participate of an essence divine.
What has not man effected by the boldness of his conceptions and the adventurousness of his spirit? The achievements of human genius have appeared so incredible, till they were thoroughly examined, and slowly established their right to general acceptance, that the great heroes of intellect were universally regarded by their contemporaries as dealers in magic, and implements of the devil. The inventor of the art of printing, that glorious instrument for advancing the march of human improvement, and the discoverer of the more questionable art of making gunpowder, alike suffered under this imputation. We have rendered the seas and the winds instruments of our pleasure, "exhausted the old world, and then discovered a new one," have drawn down lightning from heaven, and exhibited equal rights and independence to mankind. Still however it is incumbent on us to be no less wary and suspicious than we are bold, and not to imagine, because we have done much, that we are therefore able to effect every thing.
As was stated in the commencement of this Essay, we know our own sensations, and we know little more. Matter, whether in its primary or secondary qualities, is certainly not the sort of thing the vulgar imagine it to be. The illustrious Berkeley has taught many to doubt of its existence altogether; and later theorists have gone farther than this, and endeavoured to shew, that each man, himself while he speaks on the subject, and you and I while we hear, have no conclusive evidence to convince us, that we may not, each of us, for aught we know, be the only thing that exists, an entire universe to ourselves.
We will not however follow these ingenious persons to the startling extreme to which their speculations would lead us. But, without doing so, it will not misbecome us to be cautious, and to reflect what we do, before we take a leap into illimitable space.